Addax Tactical and Primary Weapon Systems (PWS) continually work on refining their gas piston upper systems, and when Addax informed me of some available upgrades to the Addax ATAC (Advanced Tactical AR Carbine) GPU (Gas Piston Upper) which I featured previously, I was interested.
Firearm Ready Solutions, LTD, and is now offering the Anti-tilt Buffer assembly as a drop-in cure for carrier tilt in the piston operated AR15/M16 platform.